Variable displacement pump or motor



Nov. 22, 1938. BENEDEK I 2,137,936

VARIABLE DISPLACEMENT PUMP OR MOTOR Filed April 19, 1955 4 Sheets-Sheet 1 v v gwucmm @4921 ILEKKEENEUEK- 4 4 i... 7 W Ham W "I'm 25....1755 EU m. WW

Nov. 22, 1938.

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Nov. 22, 1938. E. K. BENEDEK 2,137,936

VARIABLE DISPLACEMENT PUMP OR MOTOR Filed April 19," 1935 4 Sheets-Sheet 3 'llll/llllllb Nov.22,1938. E.K.BENEDEK VARIABLE DISPLACEMENT PUMP OR MOTOR Filed April 19, 1935 4 Sheets-Sheet 4 jwucm'com ELEK KEENEDEK Patented Nov, 22 1938 UNITED STATES PATE T o Fic vnam'ntn nrsgggzzi mm rum on Elek' K. Benedek, Bucyrus, Ohio 7 Application April 19, 1935, Serial No. 11,312

10 Claims.

This invention relates to variable displacement pumps and motors of the rotary radial piston typeand is an improvement in'the structure de-' scribed in and a continuation in part of my co- 5 pending application Serial No. '726,961, filed May In my said copending application a driving relation is effected between the piston carrying barponent parts thereof relative to the barrel while l5 connecting the'parts of the reactance rotor together. As therein disclosed, the impeller barrel is provided with a. radial coupling flange having a plurality of circumferentially spaced, radially directed notches in which the piston heads reciprocate and by which they are guided during reciprocation. Between adjacent notches. suitable axially extending holes are provided in the flange through which the coupling bolts and cooperating spacers extend, the diameter of each 25 hole being so related to the diameter of the spacer and bolt extending therethrough 'as to provide a free movement of the spacer in the hole during certain strokes of the pump. Thus binding, due to-the radial and tangential components of ec- 30 centricity, is eliminated. Further, the holes are such and so related to the spacers that at the maximum' stroke position the spacer will engage the circumferential wall defining the hole and effect a positive driving coupling contact therebetween, the line of contact progressing around the entire circumference of the hole once during each revolution of the barrel.

This structure, while suitable in many applications of the pump,'has certain disadvantages. Necessarily, when the pump is operating at other than maximum stroke, the same spacers cannot contact the circumferential wall of the hole continuously throughout a complete revolution of the barrel. During such lesser strokes and during starting and stopping of the pump or motor, the reactance rotor and barrel necessarily tend to lead and lag with respect to each other more than necessary to compensate for the components of eccentricity, due to low frictional driving 50 forces. This is not so objectionable when the pump is operating at high pressure or has attained its speed, as the rolling frictional resistance between the piston assemblages and the reactance rotor is sufficient to maintain the barrel and rotor in the proper rotating relation while wall of the'openings, as there is not suflicient 5 rolling frictional resistance to drive thereactance rotor up to speed: Usually this engagement is effected under a sharp impact with resultant noise anddirect vibrations ,and impact stresses.

When operated at high' speed, these initialvibra- 10 tions often cause harmonic vibrations in the high speed parts with additional noise, wear and deterioration. 'The' same istrue-upon stopping in whichinstance the reactance rotor, already up to speed tends to overrun and lead the-barrel.

The principal object of the present invention is to improve the coupling of my copending application in a manner such that these impact stresses, vibrations and noises are, to a large extent, eliminated, or greatly reduced so that quiet and efficient rolling contact is-maintained between 1 the driving couplings thus provided and the rotors, with accompanying reduction' of fric-i vtion, vibrations and stresses which might result therefrom.

Another object is to provide a" quiet, positive driving .coupling between the rotors for use in connection with larger pumps and motors wherein the space, size of parts, forces to be withstood and initial costs are such as to'justify its use an the larger initial expenditure entailed.

A correlative objectof the invention is to effect both more quiet and smooth operation while at the same time reducing friction and maintaining more eflicient timedrelation between the bar-- rel 'and reactance rotor.

Other objects and advantages will become ap-. parent from the following specification wherein reference is' made to the drawings in which- Fig. l is a horizontal longitudinal sectional 40 view of a pump or motor embodying the principles of the present invention and is taken on a plane indicated by the line l.l of Fig.,2;' a

Fig. 2 is a vertical cross sectional view of the pump'or motor takengenerally on a plane inpling with respect to the cooperating coupling hole in the barrel flange in various adjusted eccentric positions or the barrel and reactance rotor;

Fig. 5 is a fragmentary sectional view of the primary rotor and flange shown in assembly with a modified positive coupling member for use be tween the primary and secondary rotors in connection with larger pumps and motors;

Fig. 6 is a cross sectional view taken indicated by the line 56 in Fig. 5;

Fig. 7 is a fragmentary cross sectional view of a on a plane portion of the barrel and flange of the pumpor motor in assembly with a modified semi-positive coupling means'illustrating another form of the present invention;

ing couplings illustrated in Figs. 9, 10, 11 and 12 respectively;

Fig. 17 is a sectional view corresponding to Fig. 16, showing anti-friction needle rollers in cooperation with the coupling bolts for the transmission of driving torque between the rotors;

Figs. 18 and 19 are respectively a side elevation, partly in section, and a top end elevation of a coupling bolt for use in connection with the present invention; and w I Figs. 20 to 22 inclusive are respectively a. side elevation and respective end elevations of a locking bolt for cooperation with the coupling bolt illustrated in Figs. 18 and 19.

Referring to Fig. 1, the pump or motor may comprise a rigid housing I, having an end wall.

and an integral circumferential wall, the latter being designated 2. The opposite end of the housing is closed by a suitable removable weight supporting. and plate I. A valve pintle 4 is fixedly mounted in one end of the housing I and protrudes axially thereof toward the end plate 3. Within the housing is mounted a piston carrying rotor or barrel 5 which is supported near each of its ends in anti-friction radial and axial thrust bearings 6, arranged one set near each end of the barrel. From the end of the barrel adjacent the plate 3 extends the main impeller shaft I which is preferably integral with the barrel and protrudes through a bore in the plate 3 to the outside. The barrel is provided with the usual valve bore which receives and hydraulically fits the pintle l, elastic deflection .of the pintle being prevented by hydrostatic balance of the pintle which, in turn, is made possible by the use of suitable sets of capillary needle bearings 8 and 9, arranged one set at each end of the valve portionoi the pintle. By the use of these needle bearings the barrel bore and pintle are held concentric'with respect to each other and, permit the pressure fluid to enter readily in the slight clearance space afforded therebetween, thereby relieving not only the needles but the sets of bear- 7 able sets of longitudinallyextending ducts respectively, in the pintle, and through these ducts with the fluid conduit system of the apparatus in a manner fully described in my copendlng application. The barrel, in turn, is provided with a plurality of circumferentially spaced radially extending piston cylinders I2 which, through ports I4, communicate with the barrel bore in position for cooperation successively with the valve ports I and I I as the barrel rotates.

The barrel is provided with an integral radially extending flange I disposed in the plane of the cylinders I2, preferably midway between its ends. A series of radially extending cylindrical guideways or notches I6, are provided in the flange I5, one such guideway for each cylinder. Carried in the respective'cylinders are reciprocable pistons Il, each having an enlarged head'IB, the leading and trailing edges of which engage the correspondingleading and trailing walls of the cylindrical guideways I6.' Both the walls of the guideways and the corresponding edges of the piston heads are arcuate about the axis of the par-.

ticular piston so that the pistons are free to rotate about their own axis unconstrainedby said guide walls while being constrained againsttransverse oscillation by the partially embracing margins of the walls of thegui'deways. Each piston head I8 is provided with a bore extending parallel'to the axis of the barrel, that is, transversely of the flange I5 and entirely unconnected with the cylinders. In each bore is mounted an operating crosspin I9 which protrudes at its ends axially beyond the sides of the piston head with which associated, capillary anti-friction needle bearings 20 being provided for'rotatably mounting the crosspin therein. The central portion of each crosspin, engaging the needle bearings III, is preferably of larger diameter than the protruding end portions for a purpose later to be described. In Figs. 2 and 3, the end retaining washers for the needle bearings are omitted for clearness in illustration.

For reciprocating the pistons during rotation of the barrel, a reactance rotor is provided, the reactance rotor comprising a pair of matched rings 23 and 24. Since the rings 23 and 24 are the same-in form and function, being merely oppositely disposed with'respect ,to each other, the ring 23 only will be described in detail.

The ring '23 is provided with an outer axially extending circumferential shoulder 25 and a radially extending flange 26 having a shoulder 26a facing toward the piston assemblages. The

' shoulders 25 and 26a engage the inner bearing race 21 of anti-friction bearings 28 when the rings are in assembled condition. Spaced inwardly toward the piston assemblages from the radial shoulder 26a. and parallel therewith is a radial shoulder 29 which terminatesat its radially inward limit in an axially extending flange 30 having an external circumferential shoulder 30a. The bearing race 21 is of sufllcient length axially so that when it is received on the shoulder 25 with its outermost end in engagement with the shoulder 26a, its opposite marginal portion overhangs the shoulder 30a, and defines'therewith an annular trough or groove opening toward the opposite ring 24 and in which are received the adjacent protruding ends of the crosspins l9. This groove, designated 32 in Fig. 2, provides one of the operating grooves for the crosspins. The ring 24 is identical with the ring 23 but, when in assembled condition to form the reactance rotor. is disposedoppositely thereto and coaxial therewith, thus providing the other operating groove for the crosspins. Obviously, these grooves are continuous circumferentially and are coaxial, one

other side.

receiving the protruding ends of the crosspins or rollers at one side of the piston assemblages and appropriate press fit so as to prevent axial displacement of the races 21 and 34. The races 2'! constitute axially spaced rings the inner surfaces of which overhanging the associated shoulders 30:; act as reactance surfaces for cooperation with the reduced diameter end portions of the cross pins I9.

The bearings 28, in turn, are mounted in a grooved external race 34 which is mounted on an internal circumferentially extending bearing surface of the reactance rotor housing or stator '35, the stator having an inwardly protruding circumferential boss 35 for strengthening it between the bearing races and firm positioning shoulders for the outer races 34 of the large bearings. The boss 36, however, is preferably of slightly less width the races 34 so that when the rings 23 and 24 are drawn together in operating position, the races 34 will not engage rigidly the boss 36 and be stressed out of normal operating alignment with the races 21 but will be free to float axially. Correspondingly, the shoulders 30 are of such dimension axially relative to the protruding ends of the pins 19 that slight axial clearance is provided between the ends of the pins and the sho'ulders'29. By forming the protruding endsof the crosspins of less diameter than the central portions shoulders are provided at the junctures with the large portion. The innermost ends or radial face portions ofthe race rings 21 and the rings 23 and 24 lie alongside the'pistonportions l8, and the shoul-. ders formed at the junctures of the large diameter cross pin portions and the reduced diameter end portions engage the radial face portions of the race rings 21 and the rings 23 and without clearance so that the pins are guided during their rolling motion by these shoulders and not by the radial shoulders 23 of the ring 23. The shoulders between the large and small diameter portions of the crosspin provide a rolling shoulder engagement for constraining the pins to fixed axial position within the plunger portion while providing proper rolling engagement. By this reduction of the size of the pins at the end portions a reduction in the diameter of the reactance rings and'in the diameter and size of all the parts of the pump cooperating therewith may be effected and centrifugal and inertia forces reduced. .Retainer washers,-better illustrated in Fig. 1,- are pressed into the bores of the heads l8 at both ends of the needle bearing to retain the needles therein and provide liquid tight chambers' for lubrication thereon. v The adjustable housing'35, in'turn, is provided with diametrically opposite plane bearing surfaces 38 which are engaged by complementary flat bearing surfaces on the interior of the circumferential wall 2 of the pump housing for mounting the same and the reactance rotor therein so that it may be shifted from concentric to its eccentric positions with'respect to the barrel while its axis is maintained parallel to the axis of rotation of the barrel to effect the reversal of the fluid flow of becoming unscrewed and disconnected. For permitting access to the screws 40, bores 4| and 42 are provided 'in the housing 2 and stator 35 respectively, which are aligned with the screws '40'when the stator assembly is in its center position, these bores-being closed by caps or plugs 4la after the screws 40 are fixed to prevent any grit or foreign. matter getting into the casing. Thus the screws may be tightened or unscrewed by a screw driver at will in position.

.In assembling the structure, the rings 23 and 24 are disposed in cooperating relationship'with the crosspins IS in a manner illustrated in Fig. 1. The rings, however, are provided with a plurality of axially aligned circumferentially spaced holes 43 and 44 respectively, the holes 44 being provided with threads. The holes43, at their outer ends, are counterbored so as to form shoulders for engaging the under portions 45a of the heads of coupling bolts 45. The sets of bores are disposed one between each pair of adjacent guideways l5, and

- the holes 43 are aligned axially with respect to the holes 44 for receiving the bolts 45. The holes 43 axially of the stator than the distance between and are positioned radially of the rings 23 and 24 so that they extend throughthe grooves 32. When the bolts 45 are inserted through-a coopcrating pair of aligned holes 43 and 44, tubular spacers 41 are slidably and snugly received thereon, the spacers being of sufflcient diameter so that the end portions thereof are received in the operating grooves 32. The spacers are of the proper length so that the ends abut the shoulders 29 of the opposite grooves when installed, thus positively fixing the relative spacing of the rings 23 and 24 from each other. By forming the spacers of accurate length, accuracy in the assembly is assured. In the act of assembling, the

spacers 'arenecessarily placed in the proper position and the bolts 45 inserted therethrough with their threaded ends engaging the threads of the hole 44 for drawing the rings firmly against the ends of the spacers, Instead of separate spacers, bolts threaded at both ends with enlarged central portions forming, in effect,- integral spacers, may be used and locked at each end as set forth hereinafter, but such are not aseffective for.assembly purposes. The rotor and barrel assemblages may then be rotated until the action'is found free from any binding action on the bearings, whereupon lock bolts 49 may be screwed into the holes 44 and against the ends of the bolts 45 v for holding them securely in the proper adjusted positions.

Referring next to Figs. 1, 2 and- 3 specifically, the radial flange of the barrel is provided inter,- mediate adjacent piston head guideways IS with a series of circular holes 50 having axes extending parallel to the barrel axis, one such hole being provided for each coupling bolt 45'so that the bolts 45 extend through these holes. The holes 50 are so circumferentially deployed that when the reactance rotor and barrel are concentric,

which is the neutral position of the pump, the axes of the holes are superimposed upon the axes of the bolts 45 and the bolts and spacers 41 may extend therethrough from one ring to the other. As hertofore explained, it is desirable to utilize the bolts 45 as coupling means between the reactance rotor and the barrel. This is especially desirable at lower pressures and at eccentricities smaller than the maximum eccentricity.

The

bearings 20- antifrictionally mount the pins IS in the respective plunger bores with less frictional resistance to rotation than the resistance to rotation of the ends of the pin relative to reactance 24-21. Therefore, at high pressures, the rolling frictional engagement between the crosspins l9 and their operating grooves 32, due to large radial piston loads, are suflicient enough to effect positive driving relation of the rotors while the ends of the crosspins are-rolling to and fro on the races 21 to effect the-proper relative movement thereof for compensating for tangential components of eccentricity. At reduced pressures and at reduced stroke, however, this rolling frictional engagement may be insufficient to impart the proper synchronous speed to the reactance assembly, especially upon starting and until the two have been brought up to operating speed by thepressure. Therefore, if this rolling frictional resistance were relied on solely for the driving connection, the reactance rotor would tend to lead the barrel upon slowing down and to lag behind the barrel when starting. As a result, the coupling bolts 45 or spacers 41 would strike the circumferential walls of the circular holes 50 with considerable impact, often sufllcient to'directly damage the parts, always creating noise, and often producing vibrations which, at high speed, cause damaging natural vibrations in the structure. In addition, at maximum eccentricity when the pump developes its maximum power, the greatest tangential forces are imposed on the pistons. Consequently, more positive drive is desirable for relieving the. piston of the full torque transmitting stress. For this purpose, at the maximum stroke, anti-friction roller assemblages are provided on the coupling'bolts 45 to contact with the walls of the holes 50. These assemblages are ,of such-overall dimensions, relative to the diameter of the holes 50 that at the maximum eccentricity of the reactance rotor and barrel, the rollers on the coupling bolts remain permanently in rolling contact with the circumferential walls defining the openings 50, and roll thereabout, completing one circuit for each revolution of the barrel. Thus a positive drive between the barrel and the reactance rotor is eflected at this stroke adjustment.

Having provided this positive drive effective at maximum eccentricity, it is apparent that when a lesser eccentricity is utilized, the relative path of the rollers on the bolts 45 would not be in rolling engagement with the walls defining the openings 50. Thus there is no' coupling connection between thebarrel and reactance rotor at the reduced eccentricity. Therefore, upon start- .ing and stopping, the lead and lag of the rotors would create impacts between the rollers on the pins 45 and the walls of the openings 50. In order to eliminate any severe impacts and to damp vibrations and reduce the noise, the rollers thus provided on the pins must'be such as'to absorb or relieve such impacts.

Referring to Figs. 1 .to 3, a set of "Hyatt roller bearings are provided for this purpose. Each of these rollers comprises a set of hollow spiral roller bearings 52, each of which bearings is provided with an axle 53 mounted at its ends in retainer rings 54. In such instances while the spacer is fixed on the bolt the bearings mayroll about the spacer as an inner race. An outer race forming, in effect, a rim 56 is also provided and directly engages the wall of the hole 50: The rim 56 is preferably made of hard wear resisting material such as is commonly used for races of anti-friction bearings. The rollers when made as ing in themselves.

' a sleeve or bushings as hereinafter described may be leather, mica, Micarta, Formica or other resilient material which will withstanddeterioration by oil. v "Mica-ta and fibre bushing as well as leather may be used without anti-friction elements or rollers because they are shock absorb- Steel rollers, however, do not have the shock absorbing qualities but Hyatt" bearings are formed of spirally wound steel springs and do have the required silencing and shock absorbing qualities. The anti-friction elements are desirable in the larger type of pumps and, if size permits, it is desirable to use the rim or outer ring described. In smaller pumps, however, where space is at a premium andthe forces are small, the shock absorbing bushings hereinafter described may be used instead of anti-friction rollers. The anti-friction rollers have an additional advantage, however, due to the fact that they engage the walls of the holes 50 under rolling impact, thus shock and noise is additionally 'reduced. However, when the simple bushings are used they must be shock absorbing due to the fact that'the friction on their supports is such as to preclude any appreciable 'antiefriction action. It

is desirable, of course, that the anti-friction rollers be used when the-structure is such as to warrant the cost as inthe cheaper structures using the bushings there is some slight sacrifice in efll-' ciency. When the device is used as a motor,

however, it is almost imperative to provide for easy starting and great efliciency and anti-friction driving engagement in the form of complete roller bearings is preferred. Thus any shocks are absorbed due to the resiliency of the rollers them selves, the damping action of fibre bushings, 'to the oil film maintained therebetween, and between them and the rim and between the rim and hole wall. In all cases, the oil absorbed in.

the rollers or between the bolts and the sleeves will be partially squeezed out under impact, thus affording a cushioning effect for silencing operation. The bearings used in any instance may be shock absorbing material, the particular choice depending upon the speed and torque pressures to bewithstood.

Referring to Fig. 10, Hyatt roller bearings are illustrated without an outer raceway or-rim, with thestationary spacer forming theinne'r race.

Figs. 9and 13 illustrate the use of a coil spring 60 for a similar purpose, a cooperating sleeveil being provided. The spring itself forms the spacer for; the assemblage. The spring derives a great portion of its shock absorbing quality by its ability to'maintain a complete and heavy capillary oil film thereon which must first be gradually discharged. Further, due to its yieldability, the shock isadditionally reduced.

In Figs. '11 and 15 there is illustrated a leather fiiction. It should be noted that in all instances in which the spacer is also used, since the clearance between it and the coupling bolt is slight, an additional capillary oil film is provided for reduc- 65 indicated by the various positions of S and If ing the impact stress due to gradually squeezingout of the film. The same is true as to the oil which necessarily is on the outer surface of the I coupling rollers.

the partial squeezing out of the tenacious capil- In Figs. 12, 16 and 1 7, the use of capillary cageless needle roller bearings for. this purpose isrillustrated. In Fig. 17, the'bearings 68 operate within a race 69' and on a spacer 69a on the bolt 45. In Fig. 16, an inner spacer is provided in addition to the outer-race 10a. In both instances, the impact is primarily relieved due to the anti-frictioncontact during the impact and lary oil film between the'bearing traces and cooperating parts. These bearings, however, may likewise be made of fibrous or more resilient I material for this particular purpose.

In order to better appreciate the operation of the coupling means, it is illustrated diagrammatically in Fig. 4. .Therein is shownthe relative positive of a roller at maximum and at intermediate eccentricities during a complete revolution thereof. For the purpose of illustra-' ,tion, the different positions of the axis of the bolt or rollers areshown rather than any point respect to the barreli this circle corresponding to for the additional diameter of the rollers.

the-circles 50, allowance, of course, being .made At a stroke lessthan the maximum eccentricity, the axis of the "coupling bolt will describe a smaller circle indicated by the dotted line circle in Fig. 4. It is while the bolts are relatively moving along this smaller circle that most of the impacts and stresses referred to may result. While the bolt is moving along the larger 'solid line circle it will take all the driving torque and relieve the pistons from the driving torque and. resultant bending moment for any pressure which would otherwise stress the pistons and crossheads.

More particularly, O1, O2 O12 represent twelve successive positions of the center of one of the.

holes which are rotating about the stationary axis (J1 of the pintle, 01 being in the line of the dead center position of the pistons. At maximum eccentricity, S1, S2 S12 represent the axis of the coupling bolt during the revolutions of the rotor. .01, is the axis of thebarrel or pintle, C2 theaxis of the reactance rotor, the distance therebetween, being the maximum eccentricity. I C represents an intermediate eccentricity in which the axis of the reactance rotor will be in C. Starting with the 'position to the left, designated O1, and plotting the relative movements of S1 and the .circle representing hole 50, it is apparent that during one complete revolution of the rotor andv barrel at maximum eccentricity, S1 will travel in a circle about the point O1, as

the eccentricity is an intermediate eccentricity,

\ as indicated by C; the axis of the coupling bolts will then describe a path as indicated." by the points'I, the various position during the revolutions being designated 11,12 I12. Thus in the consecutive positions of 0, I and S, each moves along a different circle, 0 moving about a circle with center at 01, I along a circle with center at C, and S along a circle with center at 02. Therefore, the consecutive positions of 0 and S and I are. not only on centers defined by the barrel and the particular eccentric center of the reactance rotor but in case of synchronous rotation they must be on parallel radius vectors, as illustrated.

It is apparent that while the positive coupling is efiected at maximum eccentricity, it is not effected normally at an intermediate eccentric ity. At maximum eccentricity, therefore, there est lever arms whereas the disadvantages resulting from noise and impacts which will be occa- 'sioned at lesser eccentricities' remain to be eliminated.- The. anti-friction rollers hereinbefore described will anti-frictionally coact with the walls defining the holes 50 as well as with they coupling bolts or spacers so that a smooth and efiicient silent drive can be obtained at all speeds and pressures.

It should be noted that in the present structure, which is assumed to be a medium size pump 'with corresponding horsepower output, that the holes 50 do not extend to the outer limit of the radial flange l5 but are set inwardly therefrom so that bridge portions, indicated at I511, are

provided, thus rendering the flange unseparated between the crosshead guideways and extremely strong and furnishing a sufficient body of material to prevent distortion of the flange or those portions thereof forming the guideways It for the pistons heads during heat treatment of the rotor. This is a very essential feature of this design in order to keep the crossheadsproperly fitted in their guideways and keep said guideways concentric-.with the cylinder bores.- .In larger pumps, however, it is easier to provide suillcient metal otherwise as suificient space is allowed so that it will not be absolutely. necessary to provide this bridge 15a. In such instances, a structure suchas illustrated in Figs. 5 and 6, may be, utilized to advantage for the purpose of positive coupling means. In. this structure, the flange of the barrel, indicated at 15, may be provided; with radial notches 16 which extend entirely to the outer periphery of theflange l5 and open therethrough, thesenotches being spaced between i the notches provided for guiding the piston heads.

"tangentially of the rotor ,The coupling bolts I9, corresponding to the'coupling bolts 45, are provided intermediate their ends with squared portions an of proper dimension to allow tangential reciprocation thereof in the openings 18 and have surfaces 'cooperable with the guiding surfaces of the openings so that the bolts 19 can oscillate tangentially relative to the heads I1 while effecting positive coupling relation between the rotors.

an n

Consequently, tangential components of eccentricity between the rotor and barrel can be compensated for through the passage 18 and-crossbolt while the radial component is concurrently to that in Figs. 5 and 6 is illustrated except that it is adapted to the smaller structures in which sufiicient metal is not provided in the barrel flange and in the 'very limited space required for providing the radial slots or notches l8. Inthe latter instance, the barrel flange, designated 82, is provided with an opening 83 corresponding to the hole 50. -Mounted on anti-friction bearings 84 within the hole 83 is a rotary driving element 85 which is free to rotate relative tothe flange and independently thereof about an axis parallel to the barrel axis. provided with a slot 81 corresponding to the slot 18 referred toin Fig. 6,-in which is received the squared portion 88 of the coupling bolt 88. Thus as the rotors rotate the element 85 may rotate relative to the barrel so that slot 81 is disposed at various angles to the radius of rotation of the barrel through the axis of the element 85'. Concurrently the coupling bolt 89 may shiftalong the slot regardless of the rotated position of the element 85 for compensating for both components of eccentricity. By this semi-floating connection a semi-positive drive may be maintained at all times within a limited space and both components of eccentricity provided for while maintainingfthe coupling engagemment; In such instance, however, the coupling bolt 89 must be rotatable about its own axis or the squared portion 88 must be made separately and be mounted for rotation on the bolt instead of integral therewith. Since the element 85 must rotate to accommodate itself to the proper working position as the barrel revolves, this action offers some resistance to the movement of the member 88 along .the slot 81 so that sudden impacts are damped thereby. 1

Having .thus described my invention, I claim: 1. In a rotary radial piston pump or motor including a barrel, piston assemblages carried thereby, a reactance rotor, means mounting said rotor for adjustment to diflerent positions where-'- in the'rotor is eccentric to the .barrel with its axis parallel to the barrel axis with axially spaced annularlportions disposed alongside the opposite sides 01 the piston assemblages and having an nular troughs therein for receiving piston actuating pins included in the said piston assemblages, a radial flange on said barrel received between the said spaced annularportions and having, a series of circumferentially spaced circular holes therethrough extending parallel to the barrel axis, coupling elements connected at the ends to the rotor and extending through said holesrespectively with their axes parallel to the barrel axis, roller means carried on said elements and coaxial therewith and disposed in said flange holes, and said roller means being smaller in diameter than their associated holes and being -so related in size that the roller means are continuously in rolling engagement with the circumferential walls of the holes "at the maximum. eccentricity of the barrel and rotor for driving the reactance rotor by the bar el, each of said roller means including a set or anti-friction rollers spaced apart slightly The element 85 is for maintaining'a capillary oil film therebetween.

2. In a rotary, radial piston, variable stroke pump or motor, a barrel having a plurality of radial cylinders, an adjustable rotary reactance, radial pistons in the cylinders and cooperated with the reactance for reciprocation thereby, means connecting the pistons and reactance for relative oscillation tangentially of the path of rotation and torque transmitting relation, said reactance comprisingtwo axially separable portions positioned atopposite sides of the plane of the pistons, said barrel having axial circular passages between the pistons opening endwise of the barrel, coupling elements connecting the reactance portions'together for rotation as a unit, said coupling elements extending axially of the barrel and through the passages, spacers carried on the coupling elements and cooperating therewith and with the reactance portions for constraining the reactance portions to fixed axially spaced relation to each other, rollers mounted on said spacers respectively, and resilient cushioning means operatively interposed between and engaging the rollers and walls of the associated passages for reducing the noise otherwise incident to impacts of the rollers and associated passage walls.

3. In a rotary radial piston,.variable stroke pump or motor, a barrel having a plurality-o1 radial cylinders, an adjustable rotary reactance, radial pistons in the cylinders and cooperated with the reactance for reciprocation thereby, means connecting the pistons and reactance for relative oscillationtangentially of the path of rotation and torque transmitting relation, said reactance comprising two axially separable portions positioned at opposite sides of the plane of the pistons, said barrel having axial passages between the pistons openings endwise of the barrel, coupling elements connecting the reactance portions together for rotation as a unit,

said coupling elements extending axially of the cylinders, pistons in the'cylinders respectively, a

reactance rotor, means mounting the reactance rotor for movement to different positions wherein the rotor is eccentric to the barrel with its axis parallel to the barrel axis, said rotor comprising axially separable and spaced portions disposed alongside opposite sides of the plane of the pistons and accommodating the outerend portions of the pistons therebetween, means connecting the outer end portions of the pistons with the reactance for reciprocating the pistons and transmitting torque between the reactance and barrel through the pistons, a radial flange on the barrel accommodated between said spaced portions of the reactance and having a series of circumferentially spaced holes therethrough extending parallel to the barrel axis and between the pistons, coupling elements each connected at 2,187,986 said flange holes, resilient cushioning means op eratively interposed between and engaging each roller means and the cooperating holejwall for reducing noise otherwise incident to impactsof the rollers with the associated hole walls at less than maximum stroke, said roller means being smaller in diameter than the associated holes and the rollers and cushioning means being so related in size with respect to the associated holesthat the cushioning means are continuously in rolnng. engagement with the circumferen ial walls of the holes at maximum eccentricity or the barrel and rotor for driving the rotor by the barrel at maximum stroke.

5. In a rotary, radial piston, variable stroke pump or motor, comprising a barrel having a plurality of-radial cylinders, pistons carried by the cylinders respectively, piston actuating pins carried by the pistons respectively, a reactance-v rotor, means mounting said'rotor for adjustment to vary the stroke, said ieactance rotor comprising axially separable and spaced portions disposed alongside the opposite sides of the plane of the pistons and having annular, troughs therein for receiving the ends of the piston actuating pins, a radial flange on said barrel received'between the said spaced annular portions and having a series of circumferentially spaced circular holes therethrough extending parallel to the barrel axis, coupling bolts connected at the endsto the rotor portions and extending through said holes respectively with their axes parallel to the barrel axis, spacing sleeves slidably received on the bolts and bridging the space betweenthe rings and extending at their ends into said annular troughs and abutting the bottom walls oi. said troughs for positively limiting the spaced relation of the portions, anti-friction rollers "carried on said sleeves and coaxial therewith and dis-' posed in said flange holes, and said rollers bein smaller in diameter than their associated holes and-being so related in size that theroller means are continuously in rolling engagement with the circumferential walls of the holes at the maximum eccentricity of the barrel and rotor.

6.. In a rotary radial piston pumpor motor including a barrel having a plurality of radial cylinders, a flange on the barrel in the zone of the cylinders, pistons in the cylinders respectively,

said flange having radial guideways respective to the cylinders, heads on'the pistons reciprocable in said guideways and guided thereby for radial reciprocation, an adjustable reactance rotor surrounding the barrel and comprisingsaxially separable portions spaced at opposite sides ofthe zone of the pistons and accommodating the piston heads and flange therebetween, means conheating the piston heads and reactance rotor for reciprocating the piston and for transmitting torque between the rotor and barrel through the ,medium of the heads, said radial flange having a series of cir'cumferentially spaced circular holes 3 therethrough extending parallel to the barrel axis; coupling elements connected at the ends to the rotor portions and extending through said holes respectively *for connecting said rotor portions for rotation as a unit, each of said portions .having bores aligned with bores in the other portion, the bores inone of saidpo'rtions being internally screw threaded, screw coupling bolts respective to the aligned bores and received therein, each bolt having a head portion engageable with the other i said portions for drawing the rings toward ea h other and having a threaded portion cooperable with the threaded bores for constrain ing the rings from axial separation, means for locking said bolts in position, sleeves on said bolts and coacting at their ends with the rotor portions for spacing the rotor portions from each other, and roller cushioning means carried on said sleeves and in rolling engagement with the walls stroke oi! the pump or motor.

'7 In a rotary radial pisto'nxpump or motor, a rotatable barrel having a plurality or radial cylinderapistons in the cylinders respectively,

valve means for the cylinders, each piston having a portion with a transverse bore therethrough parallel'to the barrel axis, a rotary reactance means surrounding the barrel and'mounted for adjustment to different positions 01 eccentricity relative thereto and'including a pair of rings spaced apart axially from each other for accommodating the'sald piston portions therebetween with operative clearance, reactance surfaces on the rings, cross pins carried by the'pistons respectively, each cross pin comprising a large diameter central'portion antifrictionally mounted of said openings continuously during maximum in and substantially coextensive with the transverse bore of the associated piston and end por-.

tions of less diameter extending axially of the pin from and beyond the largediameter portion whereby radial shoulders are formed on the cross p n at the juncture of said large and small diame'ter portions, said extending end portions being in rolling engagement with said ring surfaces respectively, and said rings having radial face portions alongside the piston portions in engagement with, said shoulders and constraining each piston from rotation about its .axis.

. 8.; ma rotary radial plunger pump or motor including a rotatable barrel having a plurality of radial cylinders, valve means in valving coop- I .eration with the cylinders, solid plungers in said to the reactance.

cylinders, and a reactance surrounding the barrel or actuating the plungers consequent. upon'rotation of the barrel, each plunger having a bore extending parallel to the barrel axis and entirely unconnected with the cylinders, a load transmit- 9. In a rotary radial piston pump or motor, a rotatable barrel having a'plurality of'radial cylinders, pistonsin the cylinders respectively, vvalve means for the cylinders, each piston having a portion with a transverse bore therethrough parallel to the barrel axis, a rotary reactance means surrounding the barrel and mounted eccentrically reltaivethereto and including apair of rings-spaced apart axially from each other for accommodating the said piston portions therebetween with operative clearance, reactance surfaces on the rings, cross pins carried by the pis-.

tons respectively, each cross-pin comprising a large diameter central portion antifrictionally mounted in and substantially coextensive with the transverse bore of the associated piston and encl'portions of less diameter extending axially of the pin-from and beyond the large diameter portion whereby radial shoulders are formed on --the cross pin at the juncture of said large and small diameter portions, said extending end por;

tions being in rolling engagementwith said ring surfaces, respectively, and said rings having raformed with a plurality of spaced circular holes extending parallel to the barrel rotor axis and being deployed circumferentially around said axis; and means for transmitting torque between said two rotors and having surfaces in rolling engagement respectively with the walls of said holes, said means including respectively sets of antifriction rollers, the rollers of each set being spaced slightly apart for maintaining a cushioning capillary oil film therebetween.

ELEK K. BENEDEK. 

